1. Field of the Invention
This invention relates to a standard measurement scale and markers for defining a standard measurement scale, which are used in photogrammetric analytical measurement systems.
2. Description of the Related Art
For example, photogrammetry measurement is carried out at a traffic accident site. Namely, the traffic accident site is photographed by a camera or cameras, and a survey map is established on the basis of pictures photographed by the camera. Before real distances and lengths can be reproduced on the survey map, a standard measurement scale must be recorded in the pictures.
Conventionally, the standard measurement scale is defined by at least two cone-shaped markers which are formed of, for example, a suitable plastic material. In particular, for example, at a traffic accident site, two markings are indicated on the ground with chalk, and a distance between the markings is obtained using a measuring tape. Then, the cone-shaped markers are positioned at the respective indications. Thereafter, the traffic accident site is photographed by the camera(s), such that the cone-shaped markers are included in the field of view to be photographed.
Before a survey map can be exactly drawn, the cone-shaped markers must be positioned with respect to the indications on the ground, such that an apex of each cone-shaped marker is just above the corresponding indication, because each of the apexes of the cone-shaped markers serves as a reference point for defining a standard measurement scale.
Nevertheless, it is difficult and troublesome to align the apex of the marker with the indication, because the indication is lost from sight due to the enlarged bottom of the cone-shaped marker during positioning. Further, when the ground is not horizontal, i.e., when the ground is sloped, the positioning of the cone-shaped marker is further complicate, because a fine positional adjustment of the cone-shaped marker is necessary before the apex of the cone-shaped marker can exactly coincide with the corresponding indication.
Also, conventionally, the apex of the cone-shaped marker is painted with a light-color, such as white, yellow or the like, so that the apex is conspicuous when recorded in a photographed picture. Nevertheless, the apex of the marker is not necessarily conspicuosly recorded in the picture, e.g., when the tone of color of the background is similar to the apex color.
Furthermore, it is troublesome to obtain a distance between the indications using the measuring tape. Especially, in photogrammetry, in which a reference plane must be defined by at least three reference points, it is necessary to measure the three distances between the three reference points by using the measuring tape.
Therefore, an object of the present invention is to provide a standard measurement scale, to be used in a photogrammetric measurement system, having at least three fixed reference points.
Another object of the present invention is to provide such a standard measurement scale as mentioned above, which is constituted such that the reference points can be conspicuously recorded in a photographed picture.
Yet another object of the present invention is to provide a marker for defining a standard measurement scale in a photogrammetric measurement system, which is constituted such that a reference point of the marker can be easily aligned with an indication on the ground.
Still yet another object of the present invention is to provide such a measurement-standard-scale-defining marker as mentioned above, which is constituted such that the reference point can be conspicuously recorded in a photographed picture.
In accordance with a first aspect of the present invention, there is provided a standard measurement scale, to be used in a photogrammetric measurement system, comprising a polygonal plate member having at least three apexes, which are arranged so as to define a reference plane, and each of which defines a reference point. Preferably, the three reference points are equally spaced apart from each other by a predetermined distance. Each of the triangular apexes, of the polygonal member, includes a reference point and may be marked with a conspicuous material. The conspicuous material may comprise a light color paint. Preferably, the light color paint is a fluorescent paint. The conspicuous material may comprise a piece of reflective sheet.
In accordance with a second aspect of the present invention, there is provided a standard measurement scale, to be used in a photogrammetric measurement system, comprising a light-guide plate member including a core layer containing fluorescent substances, said light-guide plate member having at least three light-emitting sites for defining respective reference points. Preferably, the three reference points are equally spaced apart from each other by a predetermined distance. Each of the light-emitting sites may be defined as a cone-shaped or polygonal-pyramidal-shaped recess formed in the light-guide plate member for emitting fluorescent radiation therefrom. Also, each of the light-emitting spots may be defined as a hemispherical projection attached to the light-guide plate member for emitting fluorescent radiation therefrom, or may be defined by at least two V-shaped grooves formed in the light-guide plate member and extending radially from the center thereof for emitting fluorescent radiation therefrom.
In accordance with a third aspect of the present invention, there is provided a standard measurement scale, to be used in a photogrammetric measurement system, comprising: a frame member, and at least three reference-point-forming elements, for defining respective reference points, arranged on the frame member so as to define a reference plane. The standard scale may further comprises a plate member mounted on the frame member. In this case, the three reference-point-forming elements are arranged on the plate member so as to define a reference plane. Preferably, the three reference points are equally spaced apart from each other by a predetermined distance.
Each of the reference-point-forming elements may be formed as a projection for defining the reference point thereof. In this case, the projection may be a light-emitting projection including an electrical lump or a light-emitting diode, and may be formed from at least two light-guide plate elements, including each a core layer containing fluorescent substances, which are arranged such that the reference point of the projection is defined by an emission of fluorescent radiation therefrom.
Also, each of the reference-point-forming elements may be formed as a cone-shaped projection or polygonal-pyramidal-shaped projection, an apex of which defines one of the reference points. In this case, the cone-shaped projection or polygonal-pyramidal-shaped projection may be coated with a fluorescent paint, or may be covered with a reflective sheet.
Further, each of the reference-point-forming elements may be formed as a polygonal-pyramidal-shaped projection constructed from at least two light-guide plate elements, including each a core layer containing fluorescent substances. Preferably, the light-guide plate elements are arranged such that the apex of the polygonal-pyramidal-shaped projection is defined by an emission of fluorescent radiation therefrom.
Furthermore, each of the reference-point-forming elements may be formed as a small circular-shaped element for defining the reference point thereof. Preferably, the small circular-shaped element is formed from a reflective sheet.
Yet further, each of the reference-point-forming elements may be formed as a circular-shaped plate element, a center of which defines one of the reference points. In this case, the circular-shaped plate element may be formed as a light-guide plate element including a core layer containing fluorescent substances. Preferably, the light-guide plate element may have: a cone-shaped recess formed at the center thereof for emitting light-rays therefrom; a polygonal-pyramidal-shaped recess formed at the center thereof for emitting fluorescent radiation therefrom; a hemispherical projection attached to the center thereof for emitting fluorescent radiation therefrom; or at least two V-shaped grooves formed therein, which extend radially from the center thereof, for emitting fluorescent radiation therefrom.
In accordance with a fourth aspect of the present invention, there is provided a standard measurement scale, to be used in a photogrammetric measurement system, comprising: a frame member, and a light-guide plate member mounted on the frame member and including a core layer containing fluorescent substances, the light-guide plate member having at least three light-emitting sites for defining respective reference points. Preferably, the three reference points are equally spaced apart from each other by a predetermined distance.
Each of the light-emitting sites may be defined as a cone-shaped recess or a polygonal-pyramidal-shaped recess formed in the light-guide plate member for emitting fluorescent radiation therefrom. Also, the light-emitting site may be defined as a hemispherical projection attached to the light-guide plate member for emitting fluorescent radiation therefrom, or may be defined by at least two V-shaped grooves formed in the light-guide member and extending radially from the center thereof for emitting fluorescent radiation therefrom.
In accordance with a fifth aspect of the present invention, there is provided a marker, to be used in a photogrammetric measurement system for defining a standard measurement scale, comprising a light-guide plate member including a core layer containing fluorescent substances and having a light emitting site for defining a reference point.
In accordance with a sixth aspect of the present invention, there is provided a marker, to be used in a photogrammetric measurement system for defining a standard measurement scale, comprising a polygonal-pyramidal-shaped optical assembly, formed from at least two light-guide plate elements, including each a core layer containing fluorescent substances, such that an apex of the polygonal-pyramidal-shaped optical assembly is defined by an emission of fluorescent radiation therefrom.
The polygonal-pyramidal-shaped optical assembly may be produced as a generally-triangular-pyramidal-shaped optical assembly, from three isosceles-triangular light-guide plate elements, in such a manner that an inner triangular-pyramidal space is defined therewithin. Preferably, two contiguous slanting side faces of two adjacent isosceles-triangular light-guide plate elements form a V-shaped trough extending along a corresponding ridgeline of the inner triangular-pyramidal space, and the predominant emission of fluorescent radiation occurs from the side faces.
Also, the polygonal-pyramidal-shaped optical assembly may be produced as a generally-quadrilateral-pyramidal-shaped optical assembly, by crosswisely interlinking two isosceles-triangular light-guide plate elements. Preferably, the predominant emission of fluorescent occurs the slanting side faces of each isosceles-triangular light-guide plate element.
Preferably, each of the isosceles-triangular light-guide plate elements has a slit formed therein, whereby the light-guide plate elements are detachably and crosswisely interlinked via the slits formed therein. In this case, the isosceles-triangular light-guide plate elements preferably have the same isosceles-triangular shape.